1. Field of the Invention
The present invention relates to a vehicle air conditioner.
2. Description of Related Art
A conventional vehicle air conditioner controls a temperature of air blown out from an evaporator by limiting a hot gas refrigerant capacity when it is determined that there is retained water on the evaporator in a heating mode operation using a hot gas refrigerant. Through this control, a defogging effect is produced on a windshield of a vehicle, and a heating capacity of the heating mode, in which the hot gas refrigerant is used, is efficiently created (e.g., JP2003-159931A corresponding to U.S. Pat. No. 6,662,579).
However, when it is determined that there is not the retained water, the hot-gas heating mode operation is started in the above conventional vehicle air conditioner if an outside air temperature is relatively high (e.g., −10° C. to 5° C.) and humidity is high (e.g., relative humidity RH: 80% or higher). In this case, a fog is easily generated on the windshield due to a little condensed water which is generated during a refrigerant collecting operation before the hot-gas heating mode operation, thereby reducing visibility of a driver of the vehicle.